Keyboard wood (5)
I believe the answer is:
ebony
'keyboard wood' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ebony that I've seen before include "Wood - Boyne (anag)" , "Tree with blackish wood" , "Very dark black" , "Black hardwood" , "Hard wood used for black piano keys and in cabinetwork" .)